Nickel is commonly electrolessly deposited from solutions containing hypophosphite reducing agent, a chelant and stabilizers, including organic acids and thiourea. Such solutions typically are operated at an acidic pH of about 4.5 to 5.5 and a moderately high temperature of about 90.degree. C. Unfortunately when such solutions are used to apply nickel coatings onto high surface area substrates such as fabrics, the baths become unstable and crash. When such baths are stabilized by reducing the operating temperature to about 55.degree. C., the plating rate and the quality of the nickel plated onto fabrics is typically diminished. For instance, the nickel often exhibits an amorphous quality, e.g. with crystallite size less than 2 nanometers (20 Angstroms), and a surface resistivity of about 10 ohms/square or more. Moreover, commercial electroless nickel solutions often contain a heavy metal such as lead or cadmium to complex with degradation products of thiourea, such as sulfur. The presence of such heavy metal often makes it environmentally difficult to treat or dispose of depleted plating baths.
An object of this invention is to provide electrolessly-deposited nickel-coated fabrics having low surface resistivity. Another object of this invention is to provide electroless nickel plating solutions essentially devoid of heavy metals, such as lead or cadmium. Yet another object of this invention is to provide methods of electrolessly plating a layer of highly conductive, phosphorus-containing, crystalline nickel.